Wang Congzhi, Xiao Yang, Xia Jingjing, Qiu Weibao, Zheng Hairong
Shenzhen Institutes of Advanced Technology, the Chinese Academy of Science, 1068 Xueyuan Avenue, Shenzhen University Town, Xili, Nanshan, Shenzhen 518055, China.
Sensors (Basel). 2016 Nov 12;16(11):1906. doi: 10.3390/s16111906.
Plane-wave ultrasound imaging (PWUS) has become an important method of ultrasound imaging in recent years as its frame rate has exceeded 10,000 frames per second, allowing ultrasound to be used for two-dimensional shear wave detection and functional brain imaging. However, compared to the traditional focusing and scanning method, PWUS images always suffer from a degradation of lateral resolution and contrast. To improve the image quality of PWUS, many different beamforming algorithms have been proposed and verified. Yet the influence of transducer structure is rarely studied. For this paper, the influence of using an acoustic lens for PWUS was evaluated. Two linear array transducers were fabricated. One was not self-focalized in the elevation direction (non-elevation-focalized transducer, NEFT); the other one was a traditional elevation-focalized transducer (EFT). An initial simulation was conducted to show the influence of elevation focusing. Then the images obtained with NEFT on a standard ultrasound imaging phantom were compared with those obtained with EFT. It was demonstrated that, in a relatively deep region, the contrast of an NEFT image is better than that of an EFT image. These results indicate that a more sophisticated design of ultrasound transducer would further improve the image quality of PWUS.
近年来，平面波超声成像（PWUS）已成为超声成像的一种重要方法，因为其帧率已超过每秒10000帧，使得超声可用于二维剪切波检测和功能性脑成像。然而，与传统的聚焦和扫描方法相比，PWUS图像的横向分辨率和对比度总是会下降。为了提高PWUS的图像质量，人们提出并验证了许多不同的波束形成算法。然而，换能器结构的影响却很少被研究。在本文中，评估了使用声学透镜对PWUS的影响。制作了两个线性阵列换能器。一个在仰角方向不自聚焦（非仰角聚焦换能器，NEFT）；另一个是传统的仰角聚焦换能器（EFT）。进行了初步模拟以显示仰角聚焦的影响。然后将用NEFT在标准超声成像体模上获得的图像与用EFT获得的图像进行比较。结果表明，在相对较深的区域，NEFT图像的对比度优于EFT图像。这些结果表明，超声换能器更精密的设计将进一步提高PWUS的图像质量。
